1 /*
2 * include/asm-h8300/processor.h
3 *
4 * Copyright (C) 2002 Yoshinori Sato
5 *
6 * Based on: linux/asm-m68nommu/processor.h
7 *
8 * Copyright (C) 1995 Hamish Macdonald
9 */
10
11 #ifndef __ASM_H8300_PROCESSOR_H
12 #define __ASM_H8300_PROCESSOR_H
13
14 /*
15 * Default implementation of macro that returns current
16 * instruction pointer ("program counter").
17 */
18 #define current_text_addr() ({ __label__ _l; _l: &&_l; })
19
20 #include <linux/compiler.h>
21 #include <asm/segment.h>
22 #include <asm/ptrace.h>
23 #include <asm/current.h>
24
rdusp(void)25 static inline unsigned long rdusp(void)
26 {
27 extern unsigned int _sw_usp;
28
29 return _sw_usp;
30 }
31
wrusp(unsigned long usp)32 static inline void wrusp(unsigned long usp)
33 {
34 extern unsigned int _sw_usp;
35
36 _sw_usp = usp;
37 }
38
39 /*
40 * User space process size: 3.75GB. This is hardcoded into a few places,
41 * so don't change it unless you know what you are doing.
42 */
43 #define TASK_SIZE (0xFFFFFFFFUL)
44
45 #ifdef __KERNEL__
46 #define STACK_TOP TASK_SIZE
47 #define STACK_TOP_MAX STACK_TOP
48 #endif
49
50 /*
51 * This decides where the kernel will search for a free chunk of vm
52 * space during mmap's. We won't be using it
53 */
54 #define TASK_UNMAPPED_BASE 0
55
56 struct thread_struct {
57 unsigned long ksp; /* kernel stack pointer */
58 unsigned long usp; /* user stack pointer */
59 unsigned long ccr; /* saved status register */
60 unsigned long esp0; /* points to SR of stack frame */
61 struct {
62 unsigned short *addr;
63 unsigned short inst;
64 } breakinfo;
65 };
66
67 #define INIT_THREAD { \
68 .ksp = sizeof(init_stack) + (unsigned long)init_stack, \
69 .usp = 0, \
70 .ccr = PS_S, \
71 .esp0 = 0, \
72 .breakinfo = { \
73 .addr = (unsigned short *)-1, \
74 .inst = 0 \
75 } \
76 }
77
78 /*
79 * Do necessary setup to start up a newly executed thread.
80 *
81 * pass the data segment into user programs if it exists,
82 * it can't hurt anything as far as I can tell
83 */
84 #if defined(CONFIG_CPU_H8300H)
85 #define start_thread(_regs, _pc, _usp) \
86 do { \
87 (_regs)->pc = (_pc); \
88 (_regs)->ccr = 0x00; /* clear all flags */ \
89 (_regs)->er5 = current->mm->start_data; /* GOT base */ \
90 (_regs)->sp = ((unsigned long)(_usp)) - sizeof(unsigned long) * 3; \
91 } while (0)
92 #endif
93 #if defined(CONFIG_CPU_H8S)
94 #define start_thread(_regs, _pc, _usp) \
95 do { \
96 (_regs)->pc = (_pc); \
97 (_regs)->ccr = 0x00; /* clear kernel flag */ \
98 (_regs)->exr = 0x78; /* enable all interrupts */ \
99 (_regs)->er5 = current->mm->start_data; /* GOT base */ \
100 /* 14 = space for retaddr(4), vector(4), er0(4) and exr(2) on stack */ \
101 (_regs)->sp = ((unsigned long)(_usp)) - 14; \
102 } while (0)
103 #endif
104
105 /* Forward declaration, a strange C thing */
106 struct task_struct;
107
108 /* Free all resources held by a thread. */
release_thread(struct task_struct * dead_task)109 static inline void release_thread(struct task_struct *dead_task)
110 {
111 }
112
113 /*
114 * Free current thread data structures etc..
115 */
exit_thread(void)116 static inline void exit_thread(void)
117 {
118 }
119
120 /*
121 * Return saved PC of a blocked thread.
122 */
123 unsigned long thread_saved_pc(struct task_struct *tsk);
124 unsigned long get_wchan(struct task_struct *p);
125
126 #define KSTK_EIP(tsk) \
127 ({ \
128 unsigned long eip = 0; \
129 if ((tsk)->thread.esp0 > PAGE_SIZE && \
130 MAP_NR((tsk)->thread.esp0) < max_mapnr) \
131 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
132 eip; })
133
134 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
135
136 #define cpu_relax() barrier()
137 #define cpu_relax_lowlatency() cpu_relax()
138
139 #define HARD_RESET_NOW() ({ \
140 local_irq_disable(); \
141 asm("jmp @@0"); \
142 })
143
144 #endif
145